Disease Threats, Conformity, and Obedience to Authority

It seems as though every academic psychologist is suddenly becoming an expert on the psychology of disease. My colleagues are all writing grants and collecting data examining how the COVID-19 pandemic might influence our friendships, our romantic relationships, or relationships with our children, our stress levels, our overall happiness, and even our politics.

But Mark Schaller was into the psychology of disease long before it became the rage. In fact, two decades ago, Schaller began pointing out that, although infectious diseases might not (then) have seemed very relevant to people living in the first world, the human mind evolved during times when people’s survival, and that of their children, was constantly under threat from infectious micro-organisms. And it turns out that the threat of infection influences our relationships with other people in numerous ways, contributing not only to prejudice against outsiders, but also to an inclination to be intrinsic conformists around the other people from inside our group.

I interviewed Professor Schaller at the last meetings of the Human Behavior and Evolution Society, back in the good old days of 2019 (six months before the first diagnosed case of COVID-19). You may remember the era, when North Americans still believed that infectious diseases were part of the ancient past, or of the remote and economically undeveloped tropics. In the interview, you can see Schaller sitting comfortably unmasked as closely packed groups of college students wander by in the background.

Beginning about 20 years ago, Schaller, working with Jason Faulkner, Justin Park, Lesley Duncan, and (later) Damian Murray, began to study the role that disease concerns might play in prejudice against unfamiliar people–who might be carrying novel pathogens and who might have different dietary and cleanliness rituals than we do. Schaller describes some of that research in the first half of the interview.

Briefly, their findings indicate that becoming concerned about disease leads to prejudice against unfamiliar others, and that this infection-based prejudice is not the same as dislike based on fear of physical harm.

In the interview Schaller talks about how the physical immune system is designed to mobilize our defenses once an infectious agent has already entered our body. But it is costly and dangerous to deal with an antigen after it enters our bodies, and our physical immune system may fail. Another line of defense is to simply avoid the pathogen in the first place -- by behaving in ways that reduce the odds of infection. What does that mean? Avoiding people who are sneezing, or who show other signs of illness, for the most part. But also avoiding unfamiliar people, who might also be carrying disease.

But hey, rather than listen to me talk about what Schaller had to say about disease and social norms, you can listen to the expert himself (who describes the research on disease during the first 15 minutes of the video).

I’ll post later about Schaller’s thought-provoking thoughts about the important lessons from the classic Milgram studies of obedience, which follow his discussion of the research on disease and social norms.

To learn more about the behavioral immune system

If you want to find out more about the research of Schaller and others who have researched the behavioral immune system, see:

• The psychological immune system: Why seeing me sneeze makes you healthier.
• The psychological immune system II: When it's healthy to be antisocial.
• Behavioral Immune System IV: Do unconscious fears of infection affect your social life?
• Smells like safe sex: Behavioral Immune system III.

If you want the in-depth story, I’d recommend the paper cited below by Schaller and Justin Park (2011) on the behavioral immune system, and why it matters. An even more in-depth treatment can be found in a 2016 paper by Damian Murray and Schaller on the implications of the behavioral immune system for how we think about and interact with other people, and its implications for public policy, politics, and culture. Meanwhile, keep wearing your mask and maintaining social distance; not only will it keep you healthier, it might even make you less prejudiced.